* [tip: x86/iopl] x86/tss: Fix and move VMX BUILD_BUG_ON()
@ 2019-11-16 11:51 tip-bot2 for Thomas Gleixner
0 siblings, 0 replies; 2+ messages in thread
From: tip-bot2 for Thomas Gleixner @ 2019-11-16 11:51 UTC (permalink / raw)
To: linux-tip-commits
Cc: Thomas Gleixner, Paolo Bonzini, Andy Lutomirski, Ingo Molnar,
Borislav Petkov, linux-kernel
The following commit has been merged into the x86/iopl branch of tip:
Commit-ID: 6b546e1c9ad2a25f874f8bc6077d0f55f9446414
Gitweb: https://git.kernel.org/tip/6b546e1c9ad2a25f874f8bc6077d0f55f9446414
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Mon, 11 Nov 2019 23:03:18 +01:00
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Sat, 16 Nov 2019 11:24:00 +01:00
x86/tss: Fix and move VMX BUILD_BUG_ON()
The BUILD_BUG_ON(IO_BITMAP_OFFSET - 1 == 0x67) in the VMX code is bogus in
two aspects:
1) This wants to be in generic x86 code simply to catch issues even when
VMX is disabled in Kconfig.
2) The IO_BITMAP_OFFSET is not the right thing to check because it makes
asssumptions about the layout of tss_struct. Nothing requires that the
I/O bitmap is placed right after x86_tss, which is the hardware mandated
tss structure. It pointlessly makes restrictions on the struct
tss_struct layout.
The proper thing to check is:
- Offset of x86_tss in tss_struct is 0
- Size of x86_tss == 0x68
Move it to the other build time TSS checks and make it do the right thing.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
---
arch/x86/kvm/vmx/vmx.c | 8 --------
arch/x86/mm/cpu_entry_area.c | 8 ++++++++
2 files changed, 8 insertions(+), 8 deletions(-)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 5d21a4a..311fd48 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1338,14 +1338,6 @@ void vmx_vcpu_load_vmcs(struct kvm_vcpu *vcpu, int cpu)
(unsigned long)&get_cpu_entry_area(cpu)->tss.x86_tss);
vmcs_writel(HOST_GDTR_BASE, (unsigned long)gdt); /* 22.2.4 */
- /*
- * VM exits change the host TR limit to 0x67 after a VM
- * exit. This is okay, since 0x67 covers everything except
- * the IO bitmap and have have code to handle the IO bitmap
- * being lost after a VM exit.
- */
- BUILD_BUG_ON(IO_BITMAP_OFFSET - 1 != 0x67);
-
rdmsrl(MSR_IA32_SYSENTER_ESP, sysenter_esp);
vmcs_writel(HOST_IA32_SYSENTER_ESP, sysenter_esp); /* 22.2.3 */
diff --git a/arch/x86/mm/cpu_entry_area.c b/arch/x86/mm/cpu_entry_area.c
index 752ad11..2c1d422 100644
--- a/arch/x86/mm/cpu_entry_area.c
+++ b/arch/x86/mm/cpu_entry_area.c
@@ -161,6 +161,14 @@ static void __init setup_cpu_entry_area(unsigned int cpu)
BUILD_BUG_ON((offsetof(struct tss_struct, x86_tss) ^
offsetofend(struct tss_struct, x86_tss)) & PAGE_MASK);
BUILD_BUG_ON(sizeof(struct tss_struct) % PAGE_SIZE != 0);
+ /*
+ * VMX changes the host TR limit to 0x67 after a VM exit. This is
+ * okay, since 0x67 covers the size of struct x86_hw_tss. Make sure
+ * that this is correct.
+ */
+ BUILD_BUG_ON(offsetof(struct tss_struct, x86_tss) != 0);
+ BUILD_BUG_ON(sizeof(struct x86_hw_tss) != 0x68);
+
cea_map_percpu_pages(&cea->tss, &per_cpu(cpu_tss_rw, cpu),
sizeof(struct tss_struct) / PAGE_SIZE, tss_prot);
^ permalink raw reply related [flat|nested] 2+ messages in thread* [patch V3 04/20] x86/tss: Fix and move VMX BUILD_BUG_ON()
@ 2019-11-13 20:42 Thomas Gleixner
2019-11-15 21:12 ` [tip: x86/iopl] " tip-bot2 for Thomas Gleixner
0 siblings, 1 reply; 2+ messages in thread
From: Thomas Gleixner @ 2019-11-13 20:42 UTC (permalink / raw)
To: LKML
Cc: x86, Andy Lutomirski, Linus Torvalds, Stephen Hemminger,
Willy Tarreau, Juergen Gross, Sean Christopherson,
H. Peter Anvin, Paolo Bonzini
From: Thomas Gleixner <tglx@linutronix.de>
The BUILD_BUG_ON(IO_BITMAP_OFFSET - 1 == 0x67) in the VMX code is bogus in
two aspects:
1) This wants to be in generic x86 code simply to catch issues even when
VMX is disabled in Kconfig.
2) The IO_BITMAP_OFFSET is not the right thing to check because it makes
asssumptions about the layout of tss_struct. Nothing requires that the
I/O bitmap is placed right after x86_tss, which is the hardware mandated
tss structure. It pointlessly makes restrictions on the struct
tss_struct layout.
The proper thing to check is:
- Offset of x86_tss in tss_struct is 0
- Size of x86_tss == 0x68
Move it to the other build time TSS checks and make it do the right thing.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
---
V2: New patch
---
arch/x86/kvm/vmx/vmx.c | 8 --------
arch/x86/mm/cpu_entry_area.c | 8 ++++++++
2 files changed, 8 insertions(+), 8 deletions(-)
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1338,14 +1338,6 @@ void vmx_vcpu_load_vmcs(struct kvm_vcpu
(unsigned long)&get_cpu_entry_area(cpu)->tss.x86_tss);
vmcs_writel(HOST_GDTR_BASE, (unsigned long)gdt); /* 22.2.4 */
- /*
- * VM exits change the host TR limit to 0x67 after a VM
- * exit. This is okay, since 0x67 covers everything except
- * the IO bitmap and have have code to handle the IO bitmap
- * being lost after a VM exit.
- */
- BUILD_BUG_ON(IO_BITMAP_OFFSET - 1 != 0x67);
-
rdmsrl(MSR_IA32_SYSENTER_ESP, sysenter_esp);
vmcs_writel(HOST_IA32_SYSENTER_ESP, sysenter_esp); /* 22.2.3 */
--- a/arch/x86/mm/cpu_entry_area.c
+++ b/arch/x86/mm/cpu_entry_area.c
@@ -161,6 +161,14 @@ static void __init setup_cpu_entry_area(
BUILD_BUG_ON((offsetof(struct tss_struct, x86_tss) ^
offsetofend(struct tss_struct, x86_tss)) & PAGE_MASK);
BUILD_BUG_ON(sizeof(struct tss_struct) % PAGE_SIZE != 0);
+ /*
+ * VMX changes the host TR limit to 0x67 after a VM exit. This is
+ * okay, since 0x67 covers the size of struct x86_hw_tss. Make sure
+ * that this is correct.
+ */
+ BUILD_BUG_ON(offsetof(struct tss_struct, x86_tss) != 0);
+ BUILD_BUG_ON(sizeof(struct x86_hw_tss) != 0x68);
+
cea_map_percpu_pages(&cea->tss, &per_cpu(cpu_tss_rw, cpu),
sizeof(struct tss_struct) / PAGE_SIZE, tss_prot);
^ permalink raw reply [flat|nested] 2+ messages in thread* [tip: x86/iopl] x86/tss: Fix and move VMX BUILD_BUG_ON()
2019-11-13 20:42 [patch V3 04/20] " Thomas Gleixner
@ 2019-11-15 21:12 ` tip-bot2 for Thomas Gleixner
0 siblings, 0 replies; 2+ messages in thread
From: tip-bot2 for Thomas Gleixner @ 2019-11-15 21:12 UTC (permalink / raw)
To: linux-tip-commits
Cc: Thomas Gleixner, Paolo Bonzini, Andy Lutomirski,
Peter Zijlstra (Intel),
Ingo Molnar, Borislav Petkov, linux-kernel
The following commit has been merged into the x86/iopl branch of tip:
Commit-ID: 4dee588dc12914966faf902932238cb09a493d1c
Gitweb: https://git.kernel.org/tip/4dee588dc12914966faf902932238cb09a493d1c
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Wed, 13 Nov 2019 21:42:44 +01:00
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Thu, 14 Nov 2019 20:15:00 +01:00
x86/tss: Fix and move VMX BUILD_BUG_ON()
The BUILD_BUG_ON(IO_BITMAP_OFFSET - 1 == 0x67) in the VMX code is bogus in
two aspects:
1) This wants to be in generic x86 code simply to catch issues even when
VMX is disabled in Kconfig.
2) The IO_BITMAP_OFFSET is not the right thing to check because it makes
asssumptions about the layout of tss_struct. Nothing requires that the
I/O bitmap is placed right after x86_tss, which is the hardware mandated
tss structure. It pointlessly makes restrictions on the struct
tss_struct layout.
The proper thing to check is:
- Offset of x86_tss in tss_struct is 0
- Size of x86_tss == 0x68
Move it to the other build time TSS checks and make it do the right thing.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20191113210104.097140143@linutronix.de
---
arch/x86/kvm/vmx/vmx.c | 8 --------
arch/x86/mm/cpu_entry_area.c | 8 ++++++++
2 files changed, 8 insertions(+), 8 deletions(-)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 5d21a4a..311fd48 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1338,14 +1338,6 @@ void vmx_vcpu_load_vmcs(struct kvm_vcpu *vcpu, int cpu)
(unsigned long)&get_cpu_entry_area(cpu)->tss.x86_tss);
vmcs_writel(HOST_GDTR_BASE, (unsigned long)gdt); /* 22.2.4 */
- /*
- * VM exits change the host TR limit to 0x67 after a VM
- * exit. This is okay, since 0x67 covers everything except
- * the IO bitmap and have have code to handle the IO bitmap
- * being lost after a VM exit.
- */
- BUILD_BUG_ON(IO_BITMAP_OFFSET - 1 != 0x67);
-
rdmsrl(MSR_IA32_SYSENTER_ESP, sysenter_esp);
vmcs_writel(HOST_IA32_SYSENTER_ESP, sysenter_esp); /* 22.2.3 */
diff --git a/arch/x86/mm/cpu_entry_area.c b/arch/x86/mm/cpu_entry_area.c
index 752ad11..2c1d422 100644
--- a/arch/x86/mm/cpu_entry_area.c
+++ b/arch/x86/mm/cpu_entry_area.c
@@ -161,6 +161,14 @@ static void __init setup_cpu_entry_area(unsigned int cpu)
BUILD_BUG_ON((offsetof(struct tss_struct, x86_tss) ^
offsetofend(struct tss_struct, x86_tss)) & PAGE_MASK);
BUILD_BUG_ON(sizeof(struct tss_struct) % PAGE_SIZE != 0);
+ /*
+ * VMX changes the host TR limit to 0x67 after a VM exit. This is
+ * okay, since 0x67 covers the size of struct x86_hw_tss. Make sure
+ * that this is correct.
+ */
+ BUILD_BUG_ON(offsetof(struct tss_struct, x86_tss) != 0);
+ BUILD_BUG_ON(sizeof(struct x86_hw_tss) != 0x68);
+
cea_map_percpu_pages(&cea->tss, &per_cpu(cpu_tss_rw, cpu),
sizeof(struct tss_struct) / PAGE_SIZE, tss_prot);
^ permalink raw reply related [flat|nested] 2+ messages in thread
end of thread, other threads:[~2019-11-16 11:51 UTC | newest]
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2019-11-13 20:42 [patch V3 04/20] " Thomas Gleixner
2019-11-15 21:12 ` [tip: x86/iopl] " tip-bot2 for Thomas Gleixner
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